Created by Robert Kirkman and Tony Moore, The Walking Dead follows a group of people struggling to survive in the wake of an epidemic that’s left the world overrun by zombies. Callies' character is the wife of police officer Rick Grimes (Lincoln) who flees with their son Carl during the apocalypse to presumed safety in Atlanta accompanied by Shane (Bernthal), the partner of her then-comatose husband. Finding the city overrun with the undead, Shane gathers a group of survivors who set up camp on the outskirts of Atlanta, where they're eventually joined by Rick.

AMC has made a six-episode commitment to the series, which is set to air in October as part of the cable channel’s annual Fearfest horror marathon.